1. Field of the Invention
This invention relates to control of vehicular operating parameters.
2. Background
It is desirable under some circumstances to limit engine performance in an automobile. For example, it may be desirable to prevent the rotational speed of an engine from exceeding a predetermined limit (i.e. as expressed in revolutions per minute (RPM)) during a break-in period of a new automobile. Likewise, it may be desirable to limit engine operation when a new or inexperienced driver will be operating the automobile. Similarly, it may be desirable to limit engine operation when the automobile is entrusted to a parking valet.
In one interface for limiting automobile engine operation, the automobile is provided with a keypad. An identification code is assigned to each driver, and a valid identification code must be entered into the keypad before the automobile will function. Once a valid code has been entered into the keypad, a processor retrieves a set of engine operating parameters (for example, maximum allowable RPM) corresponding to the identification code and forwards the parameters to an ignition control unit. In this manner, a code that permits unrestrained engine operation may be provided to the owner, while a code that permits only restricted engine operation may be provided to a novice driver or to a parking valet.
In another such control system, a set of engine operating parameters are encoded onto a key or a keychain unit that transmits them to an automobile-based receiver over a radio-frequency datalink. The receiver then forwards the engine operating parameters to an ignition control unit of the automobile.
Systems as described above may be inadequate for certain applications. For example, such systems may not be suited for use in other vehicles such as personal recreational vehicles (for example, personal watercraft). A system that requires the user to input a code before using the vehicle may be inconvenient to the user. Such a system may also allow unauthorized use of the vehicle to anyone who acquires knowledge of the code. Systems that require a keypad or-a radio-frequency link may also be too expensive, delicate, and/or unreliable for some applications.
A key or keychain unit that includes encoded engine operating parameters may be useful only with respect to one particular vehicle configuration, and the task of selecting appropriate engine operating parameters to achieve a desired result may also be nonintuitive to many users. Moreover, systems as described above do not address other concerns that may a rise with respect to personal recreational vehicles, such as controlling vehicle operation in case of the user""s separation from the vehicle.
An apparatus for controlling vehicle performance includes a data port to receive a control signal from a key. A control unit is coupled to the data port to output a vehicle operating parameter that is based on information corresponding to a vehicle performance level indicated by the control signal.